Torque-transmitting mechanisms having input housings and output hubs with friction devices splined therebetween, which are selectively engaged to provide a torque-transmitting relationship between the input housing and the hub, are employed to establish either an input drive to a planetary gearset or a reaction member for a planetary gearset.
The hub member is generally connected with the planetary gear member and may be splined internally and externally to accommodate both a rotating torque-transmitting mechanism and a stationary torque-transmitting mechanism. These hubs, which have been used, have spline members, which are formed on the full length of an outer cylindrical portion of the hub. These prior art hub members are subject to centrifugal forces or hoop stresses on the cylindrical extension of the hub, which may lead to distortion of the member and inaccurate operation of the torque-transmitting mechanism.